1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
|
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
#define BPF_NO_KFUNC_PROTOTYPES
#include <vmlinux.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include "bpf_misc.h"
#include "bpf_experimental.h"
#include "bpf_arena_common.h"
struct {
__uint(type, BPF_MAP_TYPE_ARENA);
__uint(map_flags, BPF_F_MMAPABLE);
__uint(max_entries, 2); /* arena of two pages close to 32-bit boundary*/
#ifdef __TARGET_ARCH_arm64
__ulong(map_extra, (1ull << 32) | (~0u - __PAGE_SIZE * 2 + 1)); /* start of mmap() region */
#else
__ulong(map_extra, (1ull << 44) | (~0u - __PAGE_SIZE * 2 + 1)); /* start of mmap() region */
#endif
} arena SEC(".maps");
SEC("syscall")
__success __retval(0)
int basic_alloc1(void *ctx)
{
#if defined(__BPF_FEATURE_ADDR_SPACE_CAST)
volatile int __arena *page1, *page2, *no_page, *page3;
page1 = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0);
if (!page1)
return 1;
*page1 = 1;
page2 = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0);
if (!page2)
return 2;
*page2 = 2;
no_page = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0);
if (no_page)
return 3;
if (*page1 != 1)
return 4;
if (*page2 != 2)
return 5;
bpf_arena_free_pages(&arena, (void __arena *)page2, 1);
if (*page1 != 1)
return 6;
if (*page2 != 0) /* use-after-free should return 0 */
return 7;
page3 = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0);
if (!page3)
return 8;
*page3 = 3;
if (page2 != page3)
return 9;
if (*page1 != 1)
return 10;
#endif
return 0;
}
SEC("syscall")
__success __retval(0)
int basic_alloc2(void *ctx)
{
#if defined(__BPF_FEATURE_ADDR_SPACE_CAST)
volatile char __arena *page1, *page2, *page3, *page4;
page1 = bpf_arena_alloc_pages(&arena, NULL, 2, NUMA_NO_NODE, 0);
if (!page1)
return 1;
page2 = page1 + __PAGE_SIZE;
page3 = page1 + __PAGE_SIZE * 2;
page4 = page1 - __PAGE_SIZE;
*page1 = 1;
*page2 = 2;
*page3 = 3;
*page4 = 4;
if (*page1 != 1)
return 1;
if (*page2 != 2)
return 2;
if (*page3 != 0)
return 3;
if (*page4 != 0)
return 4;
bpf_arena_free_pages(&arena, (void __arena *)page1, 2);
if (*page1 != 0)
return 5;
if (*page2 != 0)
return 6;
if (*page3 != 0)
return 7;
if (*page4 != 0)
return 8;
#endif
return 0;
}
struct bpf_arena___l {
struct bpf_map map;
} __attribute__((preserve_access_index));
SEC("syscall")
__success __retval(0) __log_level(2)
int basic_alloc3(void *ctx)
{
struct bpf_arena___l *ar = (struct bpf_arena___l *)&arena;
volatile char __arena *pages;
pages = bpf_arena_alloc_pages(&ar->map, NULL, ar->map.max_entries, NUMA_NO_NODE, 0);
if (!pages)
return 1;
return 0;
}
SEC("iter.s/bpf_map")
__success __log_level(2)
int iter_maps1(struct bpf_iter__bpf_map *ctx)
{
struct bpf_map *map = ctx->map;
if (!map)
return 0;
bpf_arena_alloc_pages(map, NULL, map->max_entries, 0, 0);
return 0;
}
SEC("iter.s/bpf_map")
__failure __msg("expected pointer to STRUCT bpf_map")
int iter_maps2(struct bpf_iter__bpf_map *ctx)
{
struct seq_file *seq = ctx->meta->seq;
bpf_arena_alloc_pages((void *)seq, NULL, 1, 0, 0);
return 0;
}
SEC("iter.s/bpf_map")
__failure __msg("untrusted_ptr_bpf_map")
int iter_maps3(struct bpf_iter__bpf_map *ctx)
{
struct bpf_map *map = ctx->map;
if (!map)
return 0;
bpf_arena_alloc_pages(map->inner_map_meta, NULL, map->max_entries, 0, 0);
return 0;
}
char _license[] SEC("license") = "GPL";
|
